SUMMARY ? PROJECT 1 The primary goal of this Program Project is to establish a quantitative and automated pipeline for the reconstruction and interpretation of highly complex cellular tomographic data. Here we will focus on development and implementation of tomogram quality assessment and validation techniques (Penczek) and on experimentally guided optimization of data collection strategies (Hanein). Specifically, in Project 1 we propose to address three aims: Aim 1: Develop experimental tools for optimization of data collection strategies Aim 2: Tomogram quality assessment based on a priori content knowledge. Aim 3: Computational methodology for assessment of tilt data and reconstruction quality These efforts complement and feed back from the highly synergistic team of PIs both of Project 2 (Volkmann) which focuses on automatic tomographic reconstruction technology, extraction of various features from the tomograms, and the analysis of distribution patterns derived from the extracted features and Project 3 that seeks to develop quantitative tools for tomogram annotation though deep learning and sub-tomogram alignment as well as interactive visualization tools (Ludtke).